Preventing Soil Erosion in Continuous Corn

With the rising use of residue from corn crops in producing cellulosic ethanol, new methods of tillage and careful application of fertilizer are needed to prevent soil erosion.

With recent increase in the cost of energy and subsequent explorations into alternative energy sources, the increased harvest of corn residue for cellulosic ethanol production is likely in the future.

This may be especially true in fields where corn is grown continuously, in part because perennially high residue amounts favor annual harvests, and also because corn residue left on the soil surface is a source of inoculum for corn diseases.

Removal of corn residue, however, may require changes in tillage for increased efficiency and protection against soil erosion. Yet, the amount of N fertilizer needed to optimize corn grain yield can vary among tillage systems due to differences in soil N cycling. Thus, understanding the response of continuous corn to fertilizer N when residue is removed in different tillage systems will be necessary for optimizing N use in such systems.

A recent article in the November-December issue of Agronomy Journal summarized the results of field experiments conducted during 2006 and 2007 at four locations in Illinois, which focused on understanding how residue removal and tillage system affect the response of continuous corn to N fertilization. The research was also presented in New Orleans, LA at the American Society of Agronomy annual meeting in November 2007.

On dark prairie-derived soils with abundant rainfall, the authors, Jeffrey Coulter of the University of Minnesota and Emerson Nafziger of the University of Illinois, observed that the economically optimum N fertilizer rate (EONR) for continuous corn was reduced by 13% with full or partial removal of corn residue when compared to no removal of residue. This was consistent for both chisel plow and no-tillage systems. Averaged across N fertilizer rates in these environments, corn grain yield was similar between no-till and chisel plow tillage systems with full removal of residue. However, with partial and no removal of residue, yields were 5 and 12% greater with the chisel plow than with the no-tillage system, respectively.

“Higher yields with tillage when residue was returned in these environments were likely due to improved seedling growth resulting from warmer soil temperatures,” said Coulter.

These results show that on productive soils with adequate rainfall, removal of residue has, at least in the short term, the potential to lower N fertilizer requirements. However, the authors warn that this advantage needs to be balanced against the need to retain adequate residue to maintain soil C and protect against erosion. While no-till continuous corn worked well with full removal of residue in these highly productive environments in the central Corn Belt, Coulter says that “no-till continuous corn may be less applicable in the northern Corn Belt when residue is removed because of heavier soils and a shorter growing season.”

In his new role as a corn cropping systems agronomist in Minnesota, Coulter believes that strip-till continuous corn might be a viable alternative to no-till when residue is removed. Research is ongoing at the Universities of Minnesota and Illinois to identify best management practices with regard to economic and environmental sustainability when corn residue is removed in corn-intensive cropping systems.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://agron.scijournals.org/cgi/content/abstract/100/6/1774.

A peer-reviewed international journal of agriculture and natural resource sciences, Agronomy Journal is published six times a year by the American Society of Agronomy, with articles relating to original research in soil science, crop science, agroclimatology and agronomic modeling, production agriculture, and software. For more information visit: http://agron.scijournals.org.

The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...